Where to Listen:
If you are a regular listener, you have heard of neonicotinoids, a class of neurotoxins used on food crops all over the state and country. And it turns out, neonics are hurting a lot more than pollinators – like fish, birds, small mammals and potentially people.
On this episode, what we know about the impacts of neonic pesticides on our bodies and how to limit exposure.
Host:
Amy Barrilleaux
Guest:
Kayla Rinderknecht, Population Health Fellow, Clean Wisconsin
Resources for You:
Episode 33: Wisconsin’s bees are acting weird. Here’s why.
Neonicotinoids and their Impact
Episode 23 Neurotixins on Our Plates
Neonicotinoids and Human Health
Transcript:
Amy Welcome to the Defender Wisconsin’s environmental podcast where we learn about issues impacting our state’s environment and we meet people who are working hard all over the state to protect our water, air, land, and climate. I’m Amy Barrilleaux. June is pollinator month and it’s hard to talk about protecting pollinators without talking about a class of chemicals widely blamed for their decline. If you are a regular listener, you have heard about neonicotinoids, a class neurotoxins used on food crops all over the state and country. And it turns out, neonics are hurting a lot more than pollinators like fish, birds, small mammals, and potentially people. On this episode, what we know about the impacts of neonic pesticides on our bodies and how to limit our exposure. That’s right now on The Defender. Since the 1990s, a new kind of pesticide has come on the scene in a big way. Neonics were supposed to be the answer to dangerous chemical pesticides. By the early 2000s, use was booming and bees were in catastrophic decline. Now researchers are raising the alarm about potential human health impacts. Joining me is Clean Wisconsin population health fellow, Kayla Rinderknecht First, I want to stress that this is really what you do, look at different kinds of pollution in our bodies.
Kayla Yeah, we just look at one contaminant to the next and try to really get a full understanding of what the potential human health impacts can be and try and share it with everyone, with the public so that we can kind of know what’s going on. We use this phrase environmental determinants of health, which is a mouthful, but these are essentially environmental factors that impact a human’s health and these include physical. Chemical and biological factors that a person encounters. So, neonics is a chemical that people are kind of beginning to realize that we encounter more than we think.
Amy So you say we encounter them more than we think. I guess before we talk about where we’re being exposed to neonics or neonicotinoids, what are they exactly?
Kayla Yeah, so neonics are a type of pesticide widely used in Wisconsin and across the United States to control insects on farm fields, but they’re also used for residential lawn and gardens and also things like flea and tick collars for pets. They’re chemically similar to nicotine, so they essentially they attack the nervous system of the insect. And they’re usually for a variety of pests like aphids, whiteflies and other sap feeding insects.
Amy We’ve known for a while that they’ve been hurting other beneficial insects like pollinators, bees, butterflies. Now, I guess we’re starting to learn that maybe not just insects. What are the other kinds of animals that we’re seeing impacts?
Kayla Yeah. So like you mentioned, we know that they’re harmful to bee populations. But in addition, in addition to that, they’ve been shown to cause behavioral and DNA damage to freshwater fish. And then also, um, we’re beginning to see a decline in grassland bird populations, um in fact, from about 2008 to 2014, neonics contributed about a 12% annual decline in Grassland bird populations specifically. So they’ve observed reduced food consumption, impaired migratory behavior, and thyroid damage in birds specifically.
Amy So this kind of impact sounds sort of similar to the impact that we’ve seen in bees, right? Cause I had Dr. James Crall on the podcast a month ago or a couple of months ago, talking about how bees, you know, they directionally impaired, like they can’t find their food anymore, or they get become socially impaired, which, you know they kind of move to the edge of the nest. Like all of these, this host of impacts. Is that kind of a them with Neonics?
Kayla It seems to be, like you mentioned, I think they both impair that migratory pattern which can influence that social aspect. So I don’t necessarily know if it’s the same exact, you know, impacts but I don’t want to assume anything but it seems like there seems to be a common trend of maybe nervous system, you you know, attacks in situations, so.
Amy Now you’re not looking at the bees or the butterflies or the fish. You are looking at human health impacts of these chemicals that are widely used. So what are the ways that people are getting exposed to neonics?
Kayla Right, so neonics have been detected in soil, groundwater, drinking water, and residue on food products. So I would say, if you take anything away from today, the three main exposure routes of neonics for humans would be drinking water food residue and household products.
Amy So what kind of household products are we talking about?
Kayla Yeah, so household products. Um, so there’s actually about 360 registered, um, household products with imidacloprid, which is a type of neonic, uh, it is the only one I can say, but it is, the main one that we need to know about as that is the one found in most household products and then also the one that we’re seeing, um exceed health based. Safety standards and groundwater sampling, but I’ll get to that, but the household products that we’re mainly seeing are residential and lawn use, so things like gardens and lawn treatment and then also pest control and houses and then again those flea and tick collars for pets.
Amy I think that one in particular, that pet collar kind of makes you feel particularly bad because we, it’s not just that we love our pets and we want to keep our pets safe, we also are constantly around our pets, and our kids are around our pet, and so we just assume that whatever is on the pet collars is safe, and now that’s maybe not so clear.
Kayla Yeah, I think, yeah, it’s kind of hard to think about or kind of come to that realization. In fact, between 2018 and 2022, flea and tick collars for pets that contain neonics caused about 1,700 pet deaths and around 1,000 human poisonings in the United States.
Amy And that’s something that should concern everybody, I’m sure.
Kayla Yes, so it might not seem like a super high number over four years, but that’s much more than we want, so we want zero.
Amy Good point, we want zero. Okay, so we’ve talked about the household exposure. What about our food? Because this is primarily used on food crops.
Kayla Right, so we know that neonics are used for crops like soybeans and corn, but in addition to that, residues of neonics have been found above health-based standards in foods such as berries, corn, like I mentioned, grapes, green beans, pears, peas, peppers, strawberries, and tomatoes. So mainly fruits and vegetables. And that comes from the US Department of Agriculture pesticide program where they test thousands of samples from US food markets for neonic residue.
Amy So this residue was higher than what should have been there.
Kayla Yes, specifically for those fruits and vegetables that I listed. Overall, the average neonic detection level for all of the samples tended to be below the safety standard. But these specific fruits and vegetable were the ones that we’re seeing exceed that.
Amy And again, these are foods that we tend to eat to be healthy, I mean, fruits and vegetables.
Kayla So, yeah, something to think about. And with that imidacloprid, there’s that, neonic again, was the most found neonic in those fruits and vegetables or in those sample studies. And it was in about 12% of all samples.
Amy All right, so we’ve got our food, our pet collars, and then there’s the one I think that has been maybe the most studied, which is our water, at least here in Wisconsin. There’s been a lot of work around figuring out how much neonic is entering our water supplies. So what do we know about that?
Kayla Yeah, so we know that about 5.3% of all private drinking wells, drinking water wells in Wisconsin are estimated to have neonics or contain neonics. And we know about 25% to 33% or a third of Wisconsinites use private wells. So it is something to note. And also, neonics have had the highest detection rate in the central sands region of the state. And in Weshara County, about over half of the wells in the Wisconsin DATCP study of wells that were vulnerable to contamination had multiple neonics detected.
Amy So you mentioned DATCP, that’s the Department of Agriculture, Trade, and Consumer Protection, which I think people may not realize tests all over the state for pesticides and other chemicals in drinking water.
Kayla I think it’s important to know that these state and federal agencies are doing so much more research than people realize that really contribute to these studies and potential findings to see if humans or human health is being impacted by some of these contaminants.
Amy And I think it’s important to call that out especially now as we’re seeing, you know, federal agencies through budget cuts and just redirecting of their resources to no longer carry out this kind of research. You have state level agencies like an agency that maybe you’ve not even really heard of, DATCP, that has for a long time been carrying out these studies including Atrazine back in the 90s and now Neonics right now. How much does somebody like you, who looks at data all the time, rely on some of this information?
Kayla The first, I mean the first place that I go is either a state or federal agency. I think, I like to say that they provide technical assistance for not only organizations like Clean Wisconsin, but organizations across the country and just for the general public. They kind of work in the background, but it’s so crucial that we have this data to show what’s going on. Otherwise, we have no, I mean, we would have no idea that neonics are entering our waterways, right?
Amy So, we know that we are being exposed on some level, all of us, but especially some folks, depending on where they live in Wisconsin more than others, to these neonicotinoids. And we know they’re particularly harmful to insects, and we’ve seen the declines in bee populations. We’ve seen our pollinators really impacted both in terms of dying and then just in able to survive because of all the neurological impacts. So then what did we look at? We looked at I guess fish and birds or how do we make the leap to people from.
Kayla Yeah, so I think starting around 2010 is when we really started to see early warning signs of potential human health impacts, as that is when studies first started to be published in relation to how neonics are impacting mammals, and then gradually started to see those limited human studies. So we know that human health affects Of neonics are currently understudied, so more research is needed, but that is essentially when we started to see more of those animal studies related to mammals.
Amy So I guess the animal studies, look at high-level exposure of neonics. So what are we finding out that high- level exposure to these pesticides could mean for people?
Kayla Yeah. So initial emerging information from animal studies and those limited human studies that I mentioned, most concern has been around the nervous system, our nervous system impacts, but other impacts could be possible. So information from animals studies specifically have been shown impaired brain growth, decreased motor activity. Uh, disrupted nervous system receptors. So that could potentially be impacting memory, cognition, and behavior. Uh, other animal studies have also shown, um, or indicated links to decreased, uh, immune system function, reduced growth rates, fewer pregnancies and higher rates of stillbirths and mammals. Meanwhile, those limited human studies. Have been found that direct exposure from sprain neonics can lead to headaches, dizziness, tiredness, eye, throat, irritation, and seizures. And then also exposure to imidacloprid. So that one specific neonic has been associated with congenital heart disease that can block blood flow and also cause holes in the heart chamber. And then I’ve also found that prenatal In childhood exposure, so pre-birth and during childhood, exposure to neonics were associated with reduced cognitive abilities, so things like learning and thinking processes.
Amy That’s a lot, that’s a long, long list. And I do want to qualify it, though, because I think any kind of chemical or any kind anything virtually at high levels could be dangerous. So what do we know about the levels that people are exposed to?
Kayla Yeah, so the total dietary intake of neonics in the United States is estimated about 10 micrograms per liter. The World Health Organization’s health-based standard that they recommend is about 10 to 200 grams per kilogram of body weight, which is kind of, which confusing even for me. It’s not very straightforward. So that’s why I definitely think, you know, more research is needed to really find this, um, this level, the safety exposure limit, um not only if dietary intake, but also in drinking water standards as well.
Amy And is there a Federal drinking water standard for neonics?
Kayla There is not. I will say that there have been about seven states have started to implement neonic policies or laws. So we know that New York became the first state to ban neonic treated seeds for commercial use it on corn and soybeans. And wheat production, and then Vermont passed a similar ban, but they intend to phase it out or phase out treated seeds entirely by 2029. So yeah, policies are starting, and we’re kind of beginning to see that bottom-up trend of starting in the states. Rather than something coming from the federal level.
Amy And we’re not trending in the best direction for use of neonicotinoids, is that right?
Kayla Um, so about in the United States, there’s around 4 million pounds of neonics applied annually, um, and over 90% of corn acreage is treated with neonics and over 50% of soybean farmers had reported using neonic treatments. Um, however, it is hard to identify current trends. Uh, of neonic use due to the United States geological survey stopped, including seed treatment estimates back in 2015. So it’s been about 10 years, but prior to that change, there was a generally, um, pretty strong increasing trend in neonic usage, um, in Wisconsin from about 1990 to 2014.
Amy So let’s talk about that for a minute, because we talked about research and how important it is, and so this is a chemical that’s primarily used as a seed treatment, and then there was a decision made that there’s not gonna be tracking of seed treatment chemicals anymore.
Kayla Yeah, so from my understanding, they stopped looking at those seed treatment estimates back in 2014 across the United States. So we don’t really have any of that data for about 10 years now.
Amy How hard is it to understand a thing, a topic, when there isn’t any data being provided?
Kayla I mean I think it’s hard.
Amy Yeah, I guess that goes without saying.
Kayla Yeah, I mean, because you want to, you know, have these evidence-based, you know, informed decisions. So when we don’t have the data to necessarily back it up or the research, it’s hard to, hard to come to conclusions. But seed treatments is important to look at as that is the most, you know, that’s the most used form of neonic treatment. It can also be directly applied to the plant or soil itself. Um, but with seed treatments, we are seeing, um, a study recently said that only about one to 10% of the neonic, um applied is actually taken up by the plant itself while the other 90% of that neonic um, you know, stays in the soil or is, um transferred to the soil where it can end up in our waterways.
Amy I understand that, so you’ve got a seed treatment, so these seeds are coated in neonicotinoids, and the seed companies are saying to the farmers, this is going to be really helpful for your pests, and the plant only takes up maybe 10% of it, and then the rest just goes into and in the soil for the next.
Kayla At least that’s what that study found. So, but, you know, the reason that, you know, it’s like, well, why are we using these? Well, they are initially celebrated because they only required one application per season, um, for their crops. And, you, they originally had perceived a low toxicity, toxicity to mammals. So that’s why, you now we’ve been using these for 30, 30 plus years.
Amy So it started out where it was like, hey, we’ve got this new kind of pesticide and it’s not gonna hurt anybody and you only have to just plant the seeds.
Kayla Sounds great. And you only have to apply it one time. So I think the shift in mindset is that new research is showing that neonics have spread beyond those agricultural fields and have damaged or is causing harm to ecosystems. So with that, it’s raising questions of, are there potential human health impacts?
Amy So it feels like, you know, we’re potentially gonna have the same conversation over and over again, because you look at things that are put out in the environment, and then once they are everywhere, people say, hey, I wonder if that’s harmful. Is that basically our system of?
Kayla That seems to be a trend with almost every environmental contaminant, right? So we’re kind of realizing, oh, these are nice and they make life easier. And right now, science is saying, oh these are safe. But as science evolves and changes, which is constant, we do have to start to look at, oh, and these might be harmful to us, especially with the amount that we’re being exposed to.
Amy And what I think is really interesting with Neonics is that they’re not even these things that work great. It seems as though, for example, with corn, you have to buy it if you are growing conventional corn, corn coated with Neonoics is all that’s available. And then the farmers aren’t seeing the yields increases that they were promised with these things. I feel like this is a case where, why does anybody use these pesticides?
Kayla Right, so I think farmers are totally valid to be concerned about their crops and the potential economic impacts, but there has been extensive research showing that there’s no overall economic benefits to farmers that use neonics for seed coating. Particularly for major field crops like corn and soybeans. So in fact, multiple analysis of soybean farms had indicated that Neonics provide negligible improvements in crop yield.
Amy So that feels like maybe there’s a window to fix some of this.
Kayla Yeah. And I think that comes with education, awareness campaigns, and really trying to show that there’s not great crop yield benefits for this. And there’s really not that much uptake from the plant or from the crop itself.
Amy So it feels a little bit like this is a moneymaker for somebody, but not the farmers and definitely not the people nearby who are getting in their water and other places. What would you advise people to do who are hearing this and thinking, okay, well, yet again I’m kind of overwhelmed by all this information and I don’t know where to start to fix it.
Kayla Yeah, I think on an individual level, you can reduce exposure by consuming organic produce and avoiding the use of lawn care and flea and tick prevention products that include neonics. So the average neonic detection among all organic commodities from that US Department of Ag study was less than 1%. Um, so I would say. Advocate for using organic produce would be something easier to start with.
Amy I’m glad you mentioned that because I think sometimes we think, well organic isn’t really different, but it is, at least in this aspect.
Kayla Yes. Yeah. In this aspect for sure.
Amy Okay. And what’s the next thing you’re studying?
Kayla That’s a great question. We’re conducting a variety of research on various environmental contaminants. This summer we’re looking at harmful algal blooms. We are also looking at hazardous air pollutants or HAPS. We looking at criteria air pollutant so that includes things like ozone, particulate matter, NO2. Um, we have some other interns working on green space access and how that’s impacting probably physical or mental health, um, which will be, uh, another interesting, uh maybe not necessarily contaminant, but a determinant of health. Um, Oh, we got, we’ve got a bunch we’re working on. There’s also, we’re also starting to look at traffic related air pollution, so traps, um will be another. That might not be a specific contaminant, but again, another environmental determinant that could be impacting people’s health.
Amy Right, and so I think it’s important that a take away from this study in particular is like it’s a little bit about where you live, too, in terms of what you’re exposed to, so people in central sands, for example, when it comes to neonics, are more at risk, and then when you look at some of these other environmental determinants of health, you’re finding, well, living here, you may be exposed to this kind of issue or have this kind access to healthy.
Kayla For sure places. Yeah, like how close do you live to a highway? You know, are you being exposed to more traffic related air pollution? Than you want to be Things like green space access. Yeah. How close do your left to a park? Do you have access to that park? Can you walk to that Park? So yeah starting to look at variety of different things for sure
Amy Well, Kayla, thanks again, I really appreciate your time today.
Kayla Yeah, thank you so much, Amy.
Amy And as always, thank you for listening to The Defender. If you like this podcast, the things you learn, the information you’re getting, share it and leave a review. It helps other people find us. And we have tons of information on Neonics, in the show notes, or on our website, cleanwisconsin.org. I’m Amy Barrilleaux, talk to you later.
